1. Field of the Invention
The present invention relates to a display switching method for an electronic timepiece, an electronic timepiece, and a display switching program for the electronic timepiece and, more specifically, relates to a method of switching a display of a screen of the electronic timepiece in accordance with an amount of data in a state of ensuring optical recognizability of a user, and particularly to technology useful for displaying in the case of a large amount of data such as measured lap time.
2. Description of the Prior Art
Generally, portable type electronic apparatuses have been designed to be small-sized and light-weighted and to have multiple functions. For example, a portable type electronic timepiece in the form of a wrist watch is provided with an additional function other than an inherent timepiece function. As such an additional function, there is a lap measuring function used for measuring lap time by an athlete or the like, or an altimeter function used for measuring an altitude by a climber or the like.
Furthermore, a display of the electronic timepiece is formed with a necessary minimum size corresponding to the small-sized and light-weighted structure of the electronic timepiece. Therefore, the display is constituted by a size for making a user optically recognize time, which is an inherent timepiece function. The size is a size sufficient for making a user optically recognize when, for example, time “12:00” or the like is displayed substantially by a full screen. Further, according to an electronic timepiece of this kind, it is known to display lap time, an altitude value of the like (hereinafter, referred to as “lap time or the like”) also by a size of display similar to that for displaying time.
Therefore, when there are a plurality of measured lap times, by successively reading lap time or the like from a memory by a CPU or an electronic timepiece and switching a screen at constant intervals, the measured lap time or the like is successively displayed. Further, display start timing or the like is measured generally when a user depresses a lap display button provided at an exterior of an electronic timepiece.
FIG. 19 shows a transitional change of a display screen for explaining a display switch timing of a conventional electronic timepiece. As shown by FIG. 19, lap time is displayed by a full display screen and is set to switch to successive data at an interval of 3 seconds.
Further, in reading data of lap time or the like from a memory of the CPU, by designating either one of a push down stack and a push up stack, it can be selected whether display is executed from the newest lap time or display is executed from the oldest lap time.
However, according to the above-described conventional electronic timepiece, the screen is switched at constant intervals and, therefore, there poses a problem that a lot of time is required for displaying, for example, all of measured lap time which is inconvenient to the user. Further, when an interval between timings of switching a screen is uniformly set to a short time period, since the switching process is fast, there poses a problem that data is liable to be overlooked and that all of the data cannot be recognized optically.